what should i have done??

the best players know when to fold AK, remember..."everybody" knows that a small pair can bet the AK. Depends more on you and your opponetns stack size, your position and how your opponent has been playing. If he/she is tight, I'd fold in a heart beat. If he's known to be a lose player, well...

Sometimes you have to fold and commend your opponent for a great bet.

AKs AKo ... the raiser reraised...hmmm...I would probably fold. He has KK or AA. Or even a smal pair. Question is, are you willing to pay to play. if the extra dollars to see the flop doesn't hurt, then pay to see 3. If it doesn't hit you at all, dump the hand when he bets out. If he doesn't bet out, then it is either a trap hand or he's worried that his little pair is not good, depending what is on the board. AK is a great hand for me, I can get away from it in a heart beat. AA and KK are the hands that can't be dumped that easily. You will not get away from them. You have to play with those.